Thanks for your post and welcome to the community forums. Sorry to hear that your SIM order has been parked. Parked orders can occur if the details on the order do not match the details that already exists in the system. This can occur if the order was meant to be a gift or delivered to an alternative address, for example. These may require additional checks and could add extra days to processing your order. hope this helps.
If not, there are a few things we can do from within the community forums, we can confirm why it's parked or cancel the park however we are unable to complete sales transactions (credit checks, take payments etc). This would still require going through the correct channels by phone.